Corner joint

ABSTRACT

A corner connector (3) joins together two orthogonally disposed sections (1, 2) with C-shaped connecting means. The sections (1,2) have two flanges (11) with a strut (12) on each projecting inwards. The corner connector (3) comprises two angular pieces (4), at least two wedging pieces (5), at least two bolts (6) and at least two clamping pieces (7). The angular pieces (4) have on each flange a wedging surface (22) that press against the nose (14) of the struts (12), and a wedging surface (28) on the side opposite the flange. The wedging piece (5) is drawn by bolt (6) over the wedging surface (28) between the flanges (20), causing the flanges (20) to be tensed against the section. The clamping pieces (7) engage on the projections (13) on the struts (12). The wedging pieces (5) tensed against the clamping pieces (7) do not cause the flanges (11) to be spread apart. This arrangement results in a joint exhibiting high bend strength and high tensile strength in particular by means of friction.

This is continuation of application Ser. No. 08/457,979, filed Jun. 1,1995 now abandoned.

BACKGROUND OF THE INVENTION

Corner joint effected between a first section with C-shaped connectingmeans and a second section with C-shaped connecting means which is at anangle to the first section, by means of a corner connector whichexhibits two flanges that rest against the sections, said flanges beingjoined to the sections by at least one attachment means and a relatedcounteracting-element, the sections exhibiting two parallel flanges anda strut on each flange on the side facing the other flange, and thecorner connector comprising two mutually moveable angle pieces. Further,the invention also relates to an angle piece for the corner connectorand the use of the corner joint.

A corner joint between a pair of sections with C-shaped connecting meansusing a corner connector is known from EP 0 452 256. This corner jointis capable of transferring some degree of bending moment. In practice ithas been found that this particular corner joint can be improvedconsiderably in terms of strength. It is a disadvantage that the cornerjoint according to EP 0 452 256 involves a considerable amount of effortfor its assembly and requires appropriately qualified personnel for itsuse.

The object of the present invention is to overcome the above mentioneddisadvantages and to propose a corner joint that can be installedwithout mistake and is such that large forces can be transmitted byfriction.

SUMMARY OF THE INVENTION

This object is achieved by way of the invention in that, on the sidefacing away from the complementary angle piece (4), the angle pieceseach exhibit a wedging face (22) along their flanges (20) restingagainst the sections (1,2) and on the opposite side of the flange awedging face (28), both sections (1,2) have on both flanges (11) a ridge(13) running parallel to the strut (12), the ridges (13) are engaged byclamping piece (7) by virtue of shape, and the angle pieces (4) arespread apart by at least one wedging piece (5) which rests against thewedging faces (28) and is braced against the related section (1,2) bysecuring means (6).

The present corner joint and the related pressing of wedges intocorresponding grooves enables large forces to be transmitted.

Advantageous versions of the present invention are presented in thefollowing specification. The first and second sections, may be made, forexample, of metal, plastic or a metal-plastic combination. Preferredmetal is aluminum and aluminum alloys. Specially preferred sections areextruded sections.

The sections are arranged at an angle to each other. The sections mayform any angle, for example from 30° to 90°, whereby an angle of 90°i.e. sections that are perpendicular to each other is normal. Means ofsecurement may be for example bolts or rivets. Counteracting elementsmay be for example wedging pieces, conical sliding blocks, groove-fitsliding blocks or wedging strips. The wedging pieces or groove-fitsliding blocks exhibit a recess or blind hole which, according to thesecuring means in question, in particular when employing bolts as themeans of securement, exhibits an internal thread. Wedging strips may forexample also exhibit one or more recesses or blind holes, likewise withinternal threads.

The clamping piece is for example a shaped part made of metal such asaluminum, an aluminum alloy, iron, steel, brass and the like. Theclamping piece features at least one recess such as a hole through whichthe securing means can pass. The clamping piece may be in the form of aparallelogram-shaped plate, through which the securing means can pass,and featuring projections at its edge. Each of the struts exhibits aridge running parallel to the strut. The ridges are usefully projectionson the struts and the struts preferably exhibit a ridge facing the freeend of the section flange which is engaged from behind by theprojections on the clamping piece. This prevents the section flangesfrom being spread apart by the action of the wedging piece on tighteningthe securing means.

The angle pieces may be shaped parts made of plastic, metal or acombination of plastic and metal; preferred are angle pieces made ofmetals such as aluminum or aluminum alloys, iron, steel, brass etc. Theangle pieces may be fabricated out of a solid mass; useful, however, arepressure die cast, cast, and/or forged angle pieces. The surfaces of theangle pieces may be provided with a roughening pattern at least in theregion of mutual contact with the sections. Such a roughening patternmay be produced by sand-blasting, grinding, grooves, spark erosion,embossing etc. The pattern of roughness is present especially on thewedging surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplified embodiments of the invention are explained in the followingwith the aid of FIGS. 1 to 4. These show:

FIG. 1: A side elevation of a corner joint

FIG. 2: A cross-section through a corner joint

FIGS. 3a-e: Side elevation and a cross-section through a cornerconnecting piece and a section through the flange of the cornerconnecting piece at two different places.

FIGS. 4a-c: Views of a clamping piece.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows schematically a corner joint effected between a horizontalfirst section 1 and, butting onto this, a vertical section 2 e.g. acolumn forming part of a frame type structure. The sections 1,2 are, forexample, extruded aluminum sections. The joint is made using one or twocorner pieces 3 each of which comprises two angle pieces 4 with flanges20 and outer face 21, three clamping pieces 7, three bolts 6 and threewedging pieces 5, e.g. conical sliding block. Section 1 may e.g. alsoform the edge of a composite panel.

FIG. 2 shows a cross-section through a corner joint 3 according toFIG. 1. Section 1 has at least one C-shaped connecting means with a baseor a cross-strut 23, two parallel flanges 11 thereon and two struts 12projecting inwards. At their free end, the struts 12 exhibit a nose 14pointing towards the cross-strut 23. Struts 12 are tapered in a wedgeshape manner towards their free end.

In the example shown here one section flange 11 is longer at its freeend than the other flange 11, this by an extension 15 which features agroove 16. This groove 16 can accommodate windows, panels, flooring,sealing strips etc.

The angle pieces 4 exhibit straight-edged wedge faces 22 on the flanges20 resting against the sections 1,2. The height of the flange 20 betweenits lower limiting edge and the wedging face corresponds approximatelyto the uninterrupted distance between the cross-strut 23 and the nose14. The lower limiting edge of the flange 20 may be flat or slightlyrounded.

The wedging face 22 running out from the outer face 21 is inclined at anangle of approx. 15° to the horizontal. The inner lying side of flange20 of angle piece 4 exhibits a wedging face 28 which is inclined at anangle e.g. of approx. 15° to the vertical. The wedging face 28 mayextend the whole length of each flange 20, or only parts of the flangemay be shaped to form wedging faces. For that purpose the cross-sectionof the flange may be tapered in regions to form the wedging faces 28.

In order to make the joint, the flanges 20 of two angle pieces 4 areinserted between the struts 12 and the cross-strut 23 whereby thewedging faces 22 are pressed against nose 14. Wedges 5 e.g. conicalsliding block are inserted below the angle pieces 4, in the region ofthe wedging faces 28; the inclination of the wedging faces of wedges 5correspond to that of the wedging faces 28 of angle pieces 4. Wedgingface 22 increases from the horizontal at a wedging angle of 5° to 30°and preferably about 15°, and wedging faces 28 deviate from the verticalby a wedging angle of 5° to 30° and preferably about 15°. In addition,the wedging angle of the wedging faces 22 of flanges 20 and the wedgingfaces 28 of wedge pieces 5 are self-restricting. A clamping piece 7, forexample a parallelogram-shaped plate is placed on the ridges 13 ofstruts 12. The projections 45 of a clamping piece 7 lie on the outerside face of the ridge 13 i.e. the projections engage the ridge 13 frombehind.

A means of securement, in the present example a bolt 6, passes throughan opening such as a drilled hole in the clamping piece 7. The thread ofthe bolt 6 engages with a thread in the wedging piece 5. On turning thebolt 6, a tensile force is applied raising the wedging piece 5 with theresult that the wedging faces 28 force the flanges 20 of angle piece 4to spread apart. The flanges 20 are thereby forced outwards and wedgedbetween the cross-strut 23 and the struts 12, in the process of whichthe wedging faces 22 slide outwards on nose 14. As the bolt 6 istightened, the inner side of projection 45 of the clamping piece engagesthe ridge 13 of struts 12 and exerts a clamping action on sections 1,2.This prevents the flanges 11 from being pushed apart by the action ofthe wedging piece 5.

Adequate stability is achieved by the present corner joint e.g. alreadyby securing one of the pairs of flanges 20 of a corner connecting piecewith two bolts, wedging pieces and clamping pieces and the other pair ofcorner pieces 20 with a bolt, a wedging piece and a clamping piece. Eachpair of flanges 20 may e.g. be secured by one, two or more bolts,wedging pieces and clamping pieces on the section in question. Insteadof two or more wedging pieces and clamping pieces on one pair offlanges, it is also possible to employ wedging strips and/or clampingstrips.

FIGS. 3a to e show an example of an angle piece 4. In FIG. 3a the anglepiece is shown from the inner lying side i.e. the side that faces theother angle piece. A--A indicates the line of section through flange 20.The corresponding cross-section is shown in FIG. 3e. The cross-sectionalong A--A refers only to the parts 19 of the flange 20 which areengaged by wedging pieces 5.

In the other regions of flange 20 the cross-section is as along sectionline B--B. This cross-section is shown in FIG. 3d.

FIG. 3b shows a view of the end of an angle piece 4 with flange 20,outer face 21 and positions 19 for location of the wedging pieces. FIG.3c shows the outward facing side of the angle piece. The outer side isindicated by the numeral 21 and the flanges 20 essentially form theangle piece 4. The wedging faces 22 are shaped by forming the flange 20or by removing surrounding material therefrom.

FIGS. 4a-c show a clamping piece 7 with opening 8 for e.g. a bolt 6 (notshown here) and the projections 45 which span the ridges 13 of struts 12of sections 11. The opening 8 is preferably a hole which is round incross-section. In its upper region the hole is wider in order toaccommodate the head of a bolt or screw.

The corner joint according to the invention is such that the forcesacting on the sections are transmitted to the corner connecting pieces.These connecting pieces transfer the forces by means of friction in thata wedge is pressed into a groove and is secured in the longitudinaldirection of the wedge, and also perpendicular to the wedge in that thegroove and wedge interlock by virtue of shape. Groove or wedge may liein the corner connecting piece or in the load-bearing section. Thedirection for pressing in is typically perpendicular to the plane inwhich both load-bearing sections lie.

If bolts are employed as a securing means, then the threads may betreated with self-restricting means such as e.g. temporary or permanentadhesives. Such adhesives are for example introduced into the thread inencapsulated form; the microcapsules of adhesive burst open under theshear forces operating as the bolt is turned. The adhesive thus releasedbonds and hardens in the thread.

The present invention may for example be employed in flame-typestructures. Frame-type structures find application e.g. in vehicle bodydesign, superstructures or bodywork or parts thereof, housings orhousing parts of vehicles such as road and railway vehicles. Included inthese are also e.g. buses for private and public transport, commercialtransport vehicles with superstructures or rear-end constructions forvehicles, power-supply vehicles etc. The present invention in relationto frame-type structures encompasses such structures containing at leastone corner joint according to the invention. Furthermore, the frame-typestructures may also find application in ships, in constructions e.g.off-shore structures such as oildrilling platforms in the open sea or inmasts of all kinds.

I claim:
 1. Corner joint, which comprises:a first section with C-shapedconnecting means having outer surfaces; a second section with C-shapedconnecting means having outer surfaces and which is at an angle to thefirst section; a corner connector located inside the outer surfaces ofthe first and second sections and including two movable angle pieceswith two connector flanges that rest against said sections, saidconnector flanges being joined to said sections by at least oneattachment means; said sections including two parallel flanges and astrut on each parallel flange on the side facing the other parallelflange; wherein each angle piece exhibits a first wedging face along theconnector flanges resting against said sections and also a secondwedging face on the side of the connector flange opposite said firstwedging face; and wherein both of said sections have on the struts ofboth parallel flanges a ridge running parallel to the strut and a noseopposed to said ridge; said connector flanges including said wedgingfaces which press against the nose on the strut; said attachment meanscomprising:a clamping piece engaging the ridges by virtue of the shapeof the clamping piece; at least one wedging piece which rests againstthe second wedging faces spreading apart the angle pieces; and asecuring means bracing the wedging piece against the angle pieces;wherein the clamping piece exerts a clamping action on said sections andwherein the wedging piece exerts a spreading action and the spreadingaction presses the angle pieces against said noses; and wherein saidsections include a cross-strut extending perpendicular to said parallelflanges and forming a groove with said strut, wherein the connectorflanges are pressed into said groove.
 2. Joint according to claim 1,wherein each of the struts includes said ridge facing a free end of saidparallel flange, and the clamping piece is a parallelogram-shaped platewhich is penetrated by the securing means and includes projections thatengage said ridges.
 3. Joint according to claim 1, wherein the wedgingpiece has wedging faces and a wedging angle of the wedging faces of theconnector flanges and wedging faces of the wedging piece areself-restricting.
 4. Joint according to claim 1, wherein the twoconnector flanges are perpendicular to each other and have an outer faceparallel to a plane defined by the connector flanges, wherein theconnector flanges starting from the outer face exhibit said firstwedging faces which are straight and the connector flanges on the sidesopposite the outer faces exhibit said second wedging faces, and thefirst wedging faces extend over the connector flange.
 5. Joint accordingto claim 4, wherein said first wedging face increases from thehorizontal at a wedging angle of 5° to 30° and said second wedging facedeviates from the vertical by a wedging angle of 5° to 30°.
 6. Jointaccording to claim 5, wherein the wedging angle of said wedging faces isabout 15°.
 7. Joint according to claim 4, wherein said angle piece isdrop forged.
 8. Joint according to claim 4, wherein said angle piece ismade of an aluminum alloy.